SEAL BEACH — Rockwell International Corp. said Thursday that two of its units have signed separate contracts to help other companies build high-speed trains for Amtrak and to develop navigation and avionics systems for the world's aviation industry.

Rockwell's Railroad Electronics division agreed to be a subcontractor in one of several bids to build high-speed trains for Amtrak. It would supply complete electronic systems for power units built by Siemens Transportation Systems Inc. in New York.

Siemens is one of six companies that Amtrak pre-qualified last October to bid as general contractor for the high-speed train project, which is designed to supply 26 passenger trains mainly in the Northeast. Amtrak is expected to award the contract, worth $450 million to $500 million, later this year.

Rockwell, based in Seal Beach, already supplies cab electronics systems for locomotives manufactured by the Electro-Motive Division of General Motors Corp.

Separately, Rockwell signed a memorandum of agreement with Deutsche Aerospace AG in Munich, Germany, a unit of Daimler Benz AG, to form a joint venture to develop avionics systems and to market key aviation technologies, such as satellite-based navigation systems.

Rockwell's Collins Commercial Avionics unit and Deutsche Aerospace's Radar and Radio Systems division would form a new company to be based in Ulm, Germany. The company will be named later this year after the joint venture is created.

Rockwell hopes the partnership will enable it to expand its satellite navigation capabilities for aircraft and helicopters to growing markets in Europe and the former Soviet Union states like Russia.